Iodine
Our basic metabolism is controlled by the thyroid gland, and the thyroid gland needs iodine in order to function properly. Iodine is also important for normal brain development in children.
Iodine has to come from the diet, because it is not made in the body. 740 million people throughout the world have iodine deficiency, which is a massive problem, but too much iodine can also cause problems. Some people think extra iodine will speed up their metabolism and help them lose weight, but too much iodine can have the opposite effect and actually shut down the action of the thyroid gland.
In our segment Dr Rosemary Stanton advised how to get enough iodine from your diet.
Iodine deficiency in Australia
Australians used to get iodine from dairy products because the solution used to clean dairy equipment left residues in milk. The dairy industry has now changed to different sterilisers, so we have to rely on other iodine sources.
Studies of pregnant women, new mothers and hospital patients with diabetes found some had low iodine levels. These results have triggered investigations to see if a lack of iodine is widespread in Australia.
Signs of iodine deficiency
feeling tired and sluggish, even though you’re getting enough sleep and have enough iron in your diet
feeling cold, even though you’re warmly dressed
If you have these symptoms see your doctor, who can arrange a simple test to test your thyroid function.
Sources of iodine
Seafood:
Any kind, fresh or canned, but mussels, oysters and prawns have the most. Seaweed is a concentrated source so you shouldn’t eat lots every day, but sushi occasionally is a good idea.
Vegetables:
The amount found in vegies varies depending on the soil they’re grown in. A lack of iodine in the soil is the major reason iodine deficiency is a huge problem in many countries including China.
Iodised salt:
Iodine is added to table salt. However many people no longer use salt at the table, and 80% of our salt now comes in the foods we buy. Until food manufacturers can be convinced to use iodised salt in their products, it is a good idea to use iodised salt whenever you need salt in cooking. Rosemary does not recommend eating extra salt to increase iodine intake as too much salt can also have adverse health consequences in causing high blood pressure.
(Note: sea salt, rock salt and vegetable salt do not provide significant quantities of extra minerals. The large crystals of sea salt may taste better, but sea salt does not have any health benefits and it does not contain iodine.)
What to do
Use iodised salt when you need salt in cooking, but remember, with any kind of salt more is not better. Eat seafood several times a week Write to bread and cereal companies asking them to use iodised salt in their products.